1 files changed, 66 insertions, 0 deletions
diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h
new file mode 100644
index 000000000000..bddd9759bab9
--- /dev/null
+++ b/include/linux/pagewalk.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_PAGEWALK_H
+#define _LINUX_PAGEWALK_H
+
+#include <linux/mm.h>
+
+struct mm_walk;
+
+/**
+ * mm_walk_ops - callbacks for walk_page_range
+ * @pud_entry:		if set, called for each non-empty PUD (2nd-level) entry
+ *			this handler should only handle pud_trans_huge() puds.
+ *			the pmd_entry or pte_entry callbacks will be used for
+ *			regular PUDs.
+ * @pmd_entry:		if set, called for each non-empty PMD (3rd-level) entry
+ *			this handler is required to be able to handle
+ *			pmd_trans_huge() pmds.  They may simply choose to
+ *			split_huge_page() instead of handling it explicitly.
+ * @pte_entry:		if set, called for each non-empty PTE (4th-level) entry
+ * @pte_hole:		if set, called for each hole at all levels
+ * @hugetlb_entry:	if set, called for each hugetlb entry
+ * @test_walk:		caller specific callback function to determine whether
+ *			we walk over the current vma or not. Returning 0 means
+ *			"do page table walk over the current vma", returning
+ *			a negative value means "abort current page table walk
+ *			right now" and returning 1 means "skip the current vma"
+ */
+struct mm_walk_ops {
+	int (*pud_entry)(pud_t *pud, unsigned long addr,
+			 unsigned long next, struct mm_walk *walk);
+	int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
+			 unsigned long next, struct mm_walk *walk);
+	int (*pte_entry)(pte_t *pte, unsigned long addr,
+			 unsigned long next, struct mm_walk *walk);
+	int (*pte_hole)(unsigned long addr, unsigned long next,
+			struct mm_walk *walk);
+	int (*hugetlb_entry)(pte_t *pte, unsigned long hmask,
+			     unsigned long addr, unsigned long next,
+			     struct mm_walk *walk);
+	int (*test_walk)(unsigned long addr, unsigned long next,
+			struct mm_walk *walk);
+};
+
+/**
+ * mm_walk - walk_page_range data
+ * @ops:	operation to call during the walk
+ * @mm:		mm_struct representing the target process of page table walk
+ * @vma:	vma currently walked (NULL if walking outside vmas)
+ * @private:	private data for callbacks' usage
+ *
+ * (see the comment on walk_page_range() for more details)
+ */
+struct mm_walk {
+	const struct mm_walk_ops *ops;
+	struct mm_struct *mm;
+	struct vm_area_struct *vma;
+	void *private;
+};
+
+int walk_page_range(struct mm_struct *mm, unsigned long start,
+		unsigned long end, const struct mm_walk_ops *ops,
+		void *private);
+int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,
+		void *private);
+
+#endif /* _LINUX_PAGEWALK_H */